Funding for this research was provided by:
Ministry of Education, Culture, Sports, Science and Technology (JP26860413)
Ministry of Health, Labour and Welfare (JP201447016A)
Text and Data Mining valid from 2018-03-13
Received: 18 January 2017
Accepted: 28 February 2018
First Online: 13 March 2018
Ethics approval and consent to participate
: The study protocol was reviewed and approved by the Medical Ethics Board of Shinshu University School of Medicine (approval number 2715). Because this study was performed anonymously and questionnaires were returned voluntarily, informed consent was not obtained from study subjects.
: Not applicable.
: The authors declare that they have no competing interests.
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